Using D-Noise for denoising photos
OptiX&trade; won't work on simple plain picture.

From the original research: Interactive Reconstruction of Monte Carlo Image Sequences using a Recurrent Denoising Autoencoder [SIGGRAPH 2017]


  We therefore frame the problem as a reconstruction of the final image (rather than denoising) from these sparse samples - (page 98:2)
  
  
  End-to-end training allows our network to automatically learn how to best utilize auxiliary pixel features, such as depth and normals, with no guidance from the user.
  


It is base on training data from IRay render engine, with all the useful feature like Depth, Normal.

If you provide a single image without these information, it will not work since OptiX treats them as a plane rather than a scene. OptiX didn't learn how to denoise a plane with noise (or bad at it).

There are a lot of denoiser to remove noise from single image, but OptiX is not the one aim to do this job.